If it wasn't Legacy, if it wasn't simply something the author gave up on it & pulled it, then it was malware that eventually was caught & pulled from AMO.

Sad part is, you're likely to never know one way or the other (purposely).

Possible it was also know as "download_flash_and_video", & possible that that ceased back in 2013.If that is the case, then it was certainly Legacy & would not work in current FF.(Likewise, being Legacy, almost certainly not malware.)

Thanks all for your replies.I was using this up until about 1 week ago and on the latest version of Firefox at the time. The link only takes you to a page that says the addon doesn't exist anymore, however I did find a link on another forum for a Firefox web extension list at this url:https://docs.google.com/spreadsheets/d/ ... edit#gid=0

I found it on row 32 on the spreadsheet and it was listed as 'ported'.

Can anyone tell me what that means?

I did find some alternatives to try out, so hopefully I won't miss 'Download Flash and Video'.